Doosan DE12T - Piston Ring Gap; Piston Ring Side Clearance; Piston Rings

9.2.9. Piston rings
1) Visual check
Replace the piston rings with new ones
if detected worn or broken when the
engine is overhauled.
2) Piston ring gap
•
Insert the piston ring into the upper por-
tion of the cylinder liner bore so that it is
held at a right angle to the cylinder liner
wall.
•
Measure the piston ring gap with a feel-
er gauge.
Replace piston rings with new ones if
the gap is beyond the limit
3) Piston ring side clearance
•
Fit the compression ring and oil ring in
the piston ring groove.
•
With a feeler gauge, measure side
clearance of each ring, and replace
either the ring or piston if the measured
value is beyond the specified limit.
- 88 -
EA4M2007
Feeler gauge
Standard Limit
Top ring 0.30 ~ 0.45 mm 1.5 mm
2nd ring 0.35 ~ 0.50 mm 1.5 mm
Oil ring 0.30 ~ 0.50 mm 1.5 mm
Standard Limit
Top ring 0.105 ~ 0.155 mm
2nd ring 0.07 ~ 0.102 mm 0.15 mm
Oil ring 0.05 ~ 0.085 mm 0.15 mm